Grzegorz JaÅkiewicz wrote:
Does anyone here have any bad experiences with the RAID card in subject ? This is in an IBM server, with 2.5" 10k drives. But we seem to observe its poor performance in other configurations as well (with different drives, different settings) in comparison with - say, what dell provides.
Older ServeRAID cards have never been reported as very fast. They were an OK controller if you just want to mirror a pair of drives or something simple like that. Their performance on larger RAID arrays is terrible compared to the LSI products that Dell uses.
However, the M5014 *is* an LSI derived product, with a proper battery-backed write cache and everything. I'm not sure if older views are even useful now. Few things to check:
-Is the battery working, and the write cache set in write-back mode? -Has read-ahead been set usefully? -Did you try to use a more complicated RAID mode than this card can handle? Those are the three easiest ways to trash performance here. -- Greg Smith 2ndQuadrant US greg@xxxxxxxxxxxxxxx Baltimore, MD PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us "PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
